The purpose of the invention is to provide an insect repellent the mosquito repelling effects of which persist for long periods even when used in a natural environment. Another purpose of the invention is to provide an insect repellent the persistence of insect repelling effects of which can be easily discerned. The insect repellent is characterized in containing pyriproxyfen and a powder wherein Bacillus sphaericus bacteria Bacillus subtilis bacteria or Bacillus thuringiensis bacteria have been mixed with livestock manure heat treated at 60 degrees to 150 degrees or a microbe containing liquid obtained by adding water to said powder.
